Finger Joint Actuator Exerciser Straight Curved dysfunction Functional Training (M) Features: Applicable caused by various reasons of the interphalangeal joint extension dysfunction.  Suitable for finger injury or long-term arthritis caused by the lack of straight or curved knuckle, knuckle cramp.  The device can be used to carry out early self rehabilitation exercise at any time and place, and is easy e and can effectively recover finger joint movement. Use the comfort sponge lining to create in the rehabilitation training does not harm the skin. Adjustable coil spring is convenience to do varying degree of training. Specification: Item Type: Finger Joint Actuator Material: Stainless Steel Options: S, M, L Size(cm/inch) Weight(g/oz) S 7 x 3 / 2.8 x 1.2 12/0.4oz M 8 x 3 / 3.1 x 1.2 11/0.4oz L 8.6 x 3 / 3.4 x 1.2 12/0.4oz Weight: Approx.11-12g Package list: 1 x Finger Joint Actuator